Temperature Settings on Moen Single Handle Tub/Shower Faucet

I just installed a single handle tub/shower faucet, monticello 3128P The way to adjust the temperature is a little confusing: there is a small gray arrow at the top of the handle, which we thought was for the temperature, but when the arrow is pointed to the left (red) the shower is cold, and to the right (blue) the shower is hot. The plumber says that the handle itself indicates the temperature, so that when the bottom part of the handle is to the left (and the gray arrow is pointing right) the shower is hot, and when the bottom part of the handle is to the right (gray arrow pointing left) the shower is cold. Is he correct? And, if so, what is the purpose of the small gray arrow?

The top of the handle should be considered like a pointer, so it it points to the left, the water should be hot. If that is not the case, then as mentioned previously, DO NOT turn off the water to the house. NOR will you remove the cartridge from the valve body. Remove the handle and adapter. Grasp the stem with a pair of pliers and rotate it halfway. Then reinstall the adapter and handle. Your plumber either does not know what he is doing, did not test the valve ahead of time, (assuming your water heater was working), or does not want to make a return trip to correct his error.

Thank you both for your replies. I assume, then, that the grey arrow is in fact the pointer which should be pointing to hot or cold, and that my plumber didn't install correctly. Sigh. Now all I have to figure out is whether to take this on or do it myself.

In either case, thanks for the clarification. I was feeling a little nutty about this.

Just an update: finally heard back from Moen, and the company, while being unaware of its own gray arrow, did confirm that the handle is not working properly, and the cartridge stem needs to be turned. I have left a message with my plumber. We'll see how far that gets me.

Just for your amusement, and to close the loop on this story, here's what happened:

Called my plumber, told him Moen said the faucet was improperly installed. He became very defensive, said he followed the instructions, that it was working properly, but if I insisted, he would come out and try and fix it. I insisted. He came out, turned off the water to the house, removed and turned the cartridge, put everything back together and it was still working backwards. He told me this isn't backwards, it's the way every faucet he has ever installed was designed. If I wanted to argue about it, take it up with Moen. He left. I came back to this thread. Read the part about not turning off the water, not turning the cartridge, just twisting the stem. I went and got my pliers, and did it myself. Two minutes later, it's working perfectly.

Moral of the story: find another plumber. You guys are amazing. THANK YOU!!!!!

I'm pretty sure that it is printed in the literature that you may have to rotate the steam 180 to get the hot and cold to resverse. Or maybe that is on the replacement cartriges. Either way having that happen is somewhat normal and that's why I always check the water temperature before I 'set' the handle in place. Glad to see you were able to figure it out and I hope you didn't have to pay anything to get him back in again.

I'm having a similar issue with a single-handle Moen shower faucet that was also incorrectly installed by a plumber (the plumber was hired through the company that installed my shower tile). The hot water comes out first and the further it's turned counter-clockwise, the colder the water gets. The water isn't very hot either. I've turned the temperature up on my hot water heater to see if that helps (although temperatures in other faucets are hotter). I've tried turning the cartridge 180 degrees to get the cold water to come out first, but turning it only 180 degrees left the faucet in the "on" position with water still pouring out. Any other suggestions? I have no gray arrow either... I'm normally pretty handy, but I'm stumped on this one.

Thanks Terry! I apologize, I was turning the nossle itself and not the entire cartridge (feeling kinda dumb now, haha). I'd suggest to others that if you aren't sure what a valve cartridge looks like then Google the replacement part to see the picture. The cartridge was also pretty stuck in there so I didn't think it actually came out. Don't forget to remove the pin at the top too and turn the main water off!

I once had a customer, who lived about 45 miles from where I was, call about a "backwards" Moen valve after he replaced the stem. I told him several times DO NOT turn off the water, DO NOT remove the cartridge, DO remove the handle, and DO rotate the stem. BUT every time he DID turn off the water and rotate the cartridge. SO I finally had to drive all the way there, do the one minute repair, and drive back. For him it was a very expensive case of not following directions.